Effect of sulphur dioxide (SO2) enrichment on growth attributes and its biochemical basis in tomato (Solanum lycopersicum L.).

Sulphur dioxide (SO2), belongs to a group of highly reactive gaseous pollutants "oxides of sulphur," that are emitted into the air upon fossil fuel burning and other sulphur-containing discharges from the industry. SO2 is known to cause damage to plantations and crops by adversely affecting the productivity and the quality of the economic produce. We hypothesized that there exists an inter and intraspecies variation with respect to the SO2 response, which can be exploited. To improve the SO2 tolerance of crop plants an experiment was, thus, conducted with three varieties of tomato (Solanum lycoperscium), var. H-414, H-445, and H-226, developed by IARI, New Delhi to assess their SO2 response in terms of the growth, yield and biochemical attributes under the ambient (~7 to 25µg SO2 m-3) and enriched SO2 (ambient SO2 + -10 to 15µg SO2 m-3). An assessment of crop utilization of SO2-S as a nutrient source suggests that the variety H-445 was the most potent, H-414 slightly able to absorb and H-226 was the least efficient. The SO2-mediated damage was observed to increase gradually following the ESO2 exposure duration in the var. H-414 as against the response in var. H-445 which showed a higher initial ESO2 damage at 0 DAE but later showed a greater recovery from 0 to 14 DAE. The SO2 enrichment of the air environment under tomato cultivation was also found to contribute towards the plant's S-requirement in variety H-445, which promoted its vegetative growth even under the stressful environment. Besides genetic variation in SO2 tolerance in tomatoes, the results also indicate greater adaptability and tolerance in var. H-445 to an elevated SO2 stress when compared to the other experimental tomato cultivars. Identification of air pollutant tolerant cultivars across crops may help protect the productivity and quality of the major dietary crops, which are likely to be threatened by climate change in the near future. [ABSTRACT FROM AUTHOR]